iSYSTEM, March 2017
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In practice, typically the iC5500 and the target cannot be powered simultaneously. To prevent hardware damage
due to the incorrect power on or power off sequence of the system, follow the next rule:
When powering the
system, switch ON the iC5500 before the target; when shutting down the system, switch OFF the target
before the iC5500!
If emulator is switched off but target is left on, forcing 5V through protection diodes on the DTM I/O pins could
activate level-translation buffers in improper way. They in turn could drive excessive current through 47E
resistors that would eventually be overheated and completely blown. The same can happen in reversed power
state and emulator is set for internal 5V source, for example.